The calculation of uranium metallic Fuel (U-10%wtZr) cell with helium coolant using SRAC 2K6

In this study, pin-shaped natural metallic uranium fuel cells with a diameter of 1.4 cm were designed with and without enrichment of 2-10% by using helium as a coolant. The calculations were conducted by using SRAC software and the results show that the greater the enrichment level, the more significant the value of the infinite-multiplication-factor (kinf), meanwhile the conversion ratio is smaller. Basically, uranium exists in two isotopic forms namely, U-235 and U-238 which are transformed into other element such as Pu-239 when they both go through fission and transmutation reactions in the reactor core. Therefore, to obtain the optimum reactor core design, the performance information of nuclear fuel cells from the variations of burn-up time needs to be taken into consideration.

Pemodelan dan Simulasi Proses Adsorpsi Gas Pengotor oleh Molecular Sieve pada Pendingin Rde dengan Software Chemcad

The purity of RDE10 helium coolant should be maintained from various impurities gas due to water/air ingress that reacts with the reflector graphite (C). These impurities are CH4, CO, CO2, H2O, H2, O2, and N2 which can initiate oxidation corrosion or carburization-decarburization so the concentration should be maintain to be a minimum. The helium coolant is purified by Helium Purification System (HPS). One of the stages in HPS is adsorption by Molecular Sieve mainly for CO2 and H2O molecules. This paper discusses the influence of pressure, known as pressure swing adsorption (PSA) on the adsorption ability of the Molecular Sieve aims to determine the most effective pressure that will be operated on Molecular Sieve column. Molecular Sieve is modeled with CHEMCAD computer code in two columns, one column for the adsorption process, and the other for the regeneration (desorption). Adsorption methods used in the analysis is the Langmuir method. Models that have been developed simulated by providing input: total flow rate of 10.5 kg/hour, 30 °C, porosity 0.7, bed height 2 m, pore diameter 5 A, and the amount of O2 and N2 impurities respective each 1 g/s. The pressure varies between 5 to 50 bars, and the Molecular Sieve adsorption capability is analyzed. Simulation results show that with the increase in pressure of 5 to 50 bar, indicating an increase in Molecular Sieve absorption capacity to CO2 is 15.90% and to H2O is 15.80%. In the SPH design, the input stream to the Molecular Sieve must be compressed until 50 bar to obtain high absorption capability of the CO2 and H2O.

Development of Single Pebble Benchmark Ex. I-2A for IAEA UAM CRP With MOOSE

Ex. I-2a is Uncertainty Analysis in Modelling (UAM) of stand-alone thermal-hydraulics in steady state. It belongs to IAEA Coordinated Research Project (CRP). In this paper, the work is divided into two steps. Firstly, a single pebble model is developed based on Multiphysics Object Oriented Simulation Environment (MOOSE). The model includes two regions: homogeneous fuel region and shell region. One physical field is concerned: solid temperature field. The field is solved in a Jacobian-free Newton–Krylov (JFNK) way in the MOOSE framework. Secondly, perturbation of thermal parameters is done. In this paper, helium coolant temperature, convective heat transfer coefficient, power density and solid conductivity are the main thermal parameters which are concerned. Different kinds of perturbation of thermal parameters are conducted. Thus, variation of temperature profile across the pebble, Doppler temperature, moderator temperature and maximum temperature could be got.

Study of Heat Transfer Processes in Modelled Core of Nuclear Reactor with Helium Coolant

The paper considers prospects of multi-purpose use of high-temperature gas (helium) nuclear reactors. The processes of hydrodynamics and heat exchange in the modelled core of the hightemperature nuclear reactor with spherical fuel elements were studied. The influence of geometrical and mode parameters on the temperature distribution was analyzed. The paper presents results of calculating unsteady regime with reduction of in consumption of coolant flow in the core.